Method for synthesizing delta-phase perovskite crystal, and delta-phase perovskite crystal produced thereby

A method of manufacturing a delta-phase perovskite crystal, the method comprising:

• Step 1 of introducing a solvent into a reactor, and then introducing an organic anion precursor represented by Chemical Formula 1 below and a metal ion precursor represented by Chemical Formula 2 below into the solvent and dissolving the same to prepare a reaction solution;
• Step 2 of heating the reaction solution to 20 to 110° C., and when the reaction solution turns yellow, introducing an anti-solvent to obtain a solution containing a precipitate;
• Step 3 of removing a colorless solution from the solution containing the precipitate of Step 2, and then performing primary washing of the precipitate with a bad solvent;
• Step 4 of performing secondary washing of the precipitate, which has undergone the primary washing, with an ether-based solvent, and filtering the same to obtain a filtrate;
• and
• Step 5 of drying the filtrate to obtain a delta-phase perovskite crystal represented by Chemical Formula 3 below:
• in the above Chemical Formulas 1 and 3, A is formamidinium (FA), methylammonium (MA), FAxMA(1-x) (0<X<1), or N(R1)4+, and R1 is a straight-chain alkyl group having 1 to 5 carbon atoms, a branched alkyl group having 3 to 5 carbon atoms, a phenyl group, an alkylphenyl group, or an alkoxyphenyl group, and
• in the above Chemical Formulas 2 and 3, B is Fe2+, Co2+, Ni2+, Cu2+, Sn2+, Pb2+, Bi2+, Ge2+, Ti2+, Eu2+, or Zr2+, and X is I−, Cl−, or Br−.